1. Field of the Invention
The present invention relates to a rotary joint, and more particularly to a rotary joint connected with a rotary element of various types of machines, for example such as machine tools, processing machines, washing machines and like machines to supply fluid such as chemical liquids, processing liquids, washing liquids and like liquids and gases to the machine through its rotary element.
2. Description of the Related Art
In general, as shown in FIG. 3, a conventional rotary joint is provided with a joint main body. This joint main body is constructed of a casing 21 and a housing 22. Rotatably mounted in this joint main body which remains stationary in operation is a rotary body 23. This rotary body 23 is connected with a corresponding rotary element of various types of machines and instruments through bearings 24. In construction, a fluid passage 25 is formed in the casing 21 and communicated with a corresponding fluid passage 26 of the rotary body 23 to permit a fluid to pass through the rotary joint.
As shown in FIG. 3, in general, a radial ball bearing is used as each of the bearings 24 for rotatably supporting the rotary body 23. In assembly operations, the ball bearing 24 has its inner race fitted to the rotary body 23, and then has its outer race fitted in the housing 22. As shown in FIG. 4, in place of the ball bearing 24, a ball-less bearing such as sliding bearings and like bearings may be used. Such ball-less bearing is constructed of an inner ring (hereinafter referred to as the inner race) 27 and an outer ring (hereinafter referred to as the outer race) 28, and often used in industry. In assembly operations, the ball-less bearing has its inner race 27 fitted to the rotary body 23, and then has its outer race 28 fitted in the housing 22, as is in the ball bearing 24.
Problems to be solved by the present invention are as follows: namely,
As described in the above, in the conventional rotary joint, the rotary body is rotatably supported by the radial ball bearings or the ball-less bearings. In either case, it is necessary for the bearing to perform its assembly operations, in which the bearing has its inner race fitted to the rotary body while its outer race fitted in the housing. However, such assembly operations of the conventional bearing take too much time and labor due to the presence of the fitting operations of the inner race and the outer race of the bearing to the rotary body and the housing of the rotary joint, respectively.